Inspired by a BAA talk last year on short period pulsating variable
stars [1], I started a program of their observation using high
resolution spectroscopy. This aimed to measure Doppler shifts between
observations, and hence relative radial velocity of the pulsating
stellar mass. The image here shows results over a single night for BE
Lyn. The 5 min sub exposures were stacked two at a time; further
stacking threatens to blur the Doppler shift as the period is only 2.3
hrs. Relative shifts were obtained from cross correlation of the
spectra (using Python with Astropy/Specutils) then combined in a
method developed in [2]. This uses all pairwise correlations to find a
value which is most self consistent across all of them. BE Lyn is
around magnitude 8.6 which, for high resolution spectroscopy is very
faint. However, while the individual spectra are quite noisy there is
enough information for the cross-correlation to work. The velocities
have been shifted to give zero mean.


[1] VSS Mtg 2023 Video 5 - Modelling Pulsating Stars by Phil Masding &
Robin Leadbeater. https://www.youtube.com/watch?v=Z865ow5BuTY.

[2] Prieto, Carlos Allende. 2007. Velocities from Cross-Correlation: A
Guide for Self-Improvement. The Astronomical Journal 134 (5):
1843–48.